auth-bundle-1 Phase 0-5 closure: demo-mode wire, named-key backfill, AuthCheck enrichment, OpenAPI schema, intermediate-ca comment refresh

Closes the 5 gaps the post-Phase-5 audit flagged on dev/auth-bundle-1.

C1: cmd/server/main.go now selects auth.NewDemoModeAuth() when
CERTCTL_AUTH_TYPE=none and falls back to auth.NewAuthWithNamedKeys
otherwise. Pre-closure, the no-op pass-through that
NewAuthWithNamedKeys returns for empty keys would have left
ActorIDKey / ActorTypeKey / TenantIDKey unpopulated and 401'd
every Phase-3.5 rbacGate-wrapped admin route + every Phase-4
RBAC handler in demo deployments. NewDemoModeAuth injects the
synthetic 'actor-demo-anon' actor seeded by migration 000029,
which holds r-admin at global scope.

C2: backfillNamedKeyActorRoles startup hook (cmd/server/auth_backfill.go)
iterates CERTCTL_API_KEYS_NAMED entries (and legacy
CERTCTL_AUTH_SECRET synthesized fallbacks) and grants r-admin
or r-viewer to each via authActorRoleRepo.Grant before the
HTTP server starts accepting requests. Idempotent via
ON CONFLICT DO NOTHING in the repo. Failures log a warning but
are non-fatal — the server still starts and the operator can
fix grants via /v1/auth/keys. Helper extracted from main.go so
the role-mapping invariant is pinned by 4 focused unit tests
(admin->r-admin, non-admin->r-viewer, empty no-op,
grant-error non-fatal, nil-logger safe).

M1: HealthHandler.AuthCheck now returns actor_id, actor_type,
tenant_id, roles, effective_permissions, and admin_via_role
when the optional AuthCheckResolver is wired (production path:
authCheckResolverAdapter wraps the postgres ActorRoleRepository
in main.go). Nil resolver preserves the legacy {status, user,
admin} contract for back-compat with pre-Bundle-1 GUIs and
test fixtures. Adds 2 regression tests + 1 fake resolver shim.

M2: refreshes the stale 'Admin gate: every method calls
auth.IsAdmin first' comment on IntermediateCAHandler — the gate
moved to router.go::rbacGate via auth.RequirePermission
middleware in Phase 3.5; the new comment block points readers
there.

M4: 11 RBAC routes (auth/me, auth/permissions, 5 role lifecycle,
2 role-permission grant/revoke, 2 actor-role grant/revoke) added
to api/openapi.yaml under the [Auth] tag with operationIds and
shared AuthRole / AuthRolePermission schemas. AuthCheck path
extended with the Bundle-1 enrichment fields. The 11 entries
removed from openapi_parity_test.go::SpecParityExceptions.

Tests: go vet + staticcheck + go test -short -count=1 green
across cmd/server/, internal/auth/, internal/api/router/, and
internal/api/handler/. New tests: 4 backfill unit tests,
2 AuthCheck M1 enrichment tests, 1 demo-mode + rbacGate chain
integration test (TestRBACGate_DemoModeChainReachesHandler).

Branch SECURITY.md (cowork/auth-bundle-1-SECURITY.md, not part
of this commit) captures the full posture of dev/auth-bundle-1
as of this closure for the operator's pre-merge review.

internal/api/handler/intermediate_ca.go

@@ -37,12 +37,15 @@ type IntermediateCAServicer interface {
 // All routes are pinned at /api/v1/issuers/{id}/intermediates and
 // /api/v1/intermediates/{id}.
 //
-// Admin gate: every method calls auth.IsAdmin first and surfaces
-// HTTP 403 for non-admin Bearer callers (M-003 admin-gating pattern,
-// matches AdminCRLCacheHandler / AdminESTHandler / AdminSCEPIntuneHandler).
-// CA hierarchy management is a high-blast-radius surface — adding a
-// child CA mints a new sub-CA cert that becomes a trust root for every
-// downstream leaf. Operators expect this gated behind admin role.
+// Bundle 1 Phase 3.5: the admin gate moved from in-handler auth.IsAdmin
+// checks to router-level auth.RequirePermission middleware (rbacGate
+// wraps the handler with the ca.hierarchy.manage permission gate before
+// the handler body runs — non-admin Bearer callers get 403 from the
+// middleware layer instead of from each handler method). CA hierarchy
+// management is a high-blast-radius surface — adding a child CA mints a
+// new sub-CA cert that becomes a trust root for every downstream leaf.
+// The router gate guarantees the only callers reaching this handler
+// hold the admin role at global scope.
 type IntermediateCAHandler struct {
 	svc IntermediateCAServicer
 }